Annual report pursuant to Section 13 and 15(d)

Benefit Plans - Change in Benefit Obligation and Plan Assets (Details)

v3.8.0.1
Benefit Plans - Change in Benefit Obligation and Plan Assets (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Defined Benefit Pension Plans      
Defined Benefit Plan, Change in Fair Value of Plan Assets      
Fair value of plan assets at beginning of period $ 285,060    
Fair value of plan assets at end of the period 314,892 $ 285,060  
Defined Benefit Pension Plans | U.S.      
Defined Benefit Plan, Change in Benefit Obligation      
Benefit obligation at beginning of period 247,418 71,605  
Service cost 1,219 2,130 $ 2,778
Interest cost 10,115 7,680 2,913
Participant contributions 0 0  
Plan curtailments 0 (1,325)  
Plan settlements (2,264) (4,772)  
Benefits paid (9,591) (5,390)  
Expenses paid 0 0  
Net transfer in(1) 0 192,120  
Actuarial (gains) losses 14,205 (14,630)  
Translation adjustment 0 0  
Benefit obligation at end of the period 261,102 247,418 71,605
Defined Benefit Plan, Change in Fair Value of Plan Assets      
Fair value of plan assets at beginning of period 198,915 52,678  
Actual return on plan assets 27,554 6,897  
Employers contributions 3,760 1,425  
Employee contributions 0 0  
Plan settlements (2,264) (4,772)  
Benefits paid (9,591) (5,390)  
Expenses paid 0 0  
Acquisitions(1) 0 148,077  
Translation adjustment 0 0  
Fair value of plan assets at end of the period 218,374 198,915 52,678
Funded status of the plans (underfunded) (42,728) (48,503)  
Defined Benefit Pension Plans | Foreign      
Defined Benefit Plan, Change in Benefit Obligation      
Benefit obligation at beginning of period 106,025 0  
Service cost 3,686 2,106 0
Interest cost 3,271 2,224 0
Participant contributions 493 300  
Plan curtailments 0 (1,204)  
Plan settlements 0 0  
Benefits paid (2,967) (1,305)  
Expenses paid (319) (66)  
Net transfer in(1) 0 99,025  
Actuarial (gains) losses (2,169) 9,804  
Translation adjustment 11,690 (4,859)  
Benefit obligation at end of the period 119,710 106,025 0
Defined Benefit Plan, Change in Fair Value of Plan Assets      
Fair value of plan assets at beginning of period 86,145 0  
Actual return on plan assets 217 8,274  
Employers contributions 3,781 921  
Employee contributions 493 300  
Plan settlements 0 0  
Benefits paid (2,967) (1,305)  
Expenses paid (319) (66)  
Acquisitions(1) 0 81,974  
Translation adjustment 9,168 (3,953)  
Fair value of plan assets at end of the period 96,518 86,145 0
Funded status of the plans (underfunded) (23,192) (19,880)  
Supplemental Retirement Plans      
Defined Benefit Plan, Change in Benefit Obligation      
Benefit obligation at beginning of period 13,225 0  
Interest cost 489 328 0
Benefits paid (1,179) (767)  
Net transfer in(1) 0 14,671  
Actuarial (gains) losses 246 (1,007)  
Benefit obligation at end of the period 12,781 13,225 0
Defined Benefit Plan, Change in Fair Value of Plan Assets      
Fair value of plan assets at beginning of period 0 0  
Employers contributions 1,179 767  
Benefits paid (1,179) (767)  
Fair value of plan assets at end of the period 0 0 0
Funded status of the plans (underfunded) (12,781) (13,225)  
Other Postretirement Benefits Plans      
Defined Benefit Plan, Change in Benefit Obligation      
Benefit obligation at beginning of period 4,620 1,296  
Service cost 21 37 39
Interest cost 174 151 57
Participant contributions 251 176  
Plan amendments 0 (443)  
Benefits paid (923) (484)  
Medical subsidies received 0 90  
Premiums paid (3) (2)  
Net transfer in(1) 0 4,868  
Actuarial (gains) losses 418 (1,057)  
Translation adjustment 54 (12)  
Benefit obligation at end of the period 4,612 4,620 1,296
Defined Benefit Plan, Change in Fair Value of Plan Assets      
Fair value of plan assets at beginning of period 0 0  
Employers contributions 675 220  
Employee contributions 251 176  
Benefits paid (923) (484)  
Medical subsidies received 0 90  
Premiums paid (3) (2)  
Fair value of plan assets at end of the period 0 0 $ 0
Funded status of the plans (underfunded) $ (4,612) $ (4,620)